interpreter/Register.h

   1 /*
   2  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef Register_h
  30 #define Register_h
  31
  32 #include "JSValue.h"
  33 #include <wtf/Assertions.h>
  34 #include <wtf/VectorTraits.h>
  35
  36 namespace JSC {
  37
  38     class CodeBlock;
  39     class ExecState;
  40     class JSActivation;
  41     class JSObject;
  42     class JSPropertyNameIterator;
  43     class ScopeChainNode;
  44
  45     struct InlineCallFrame;
  46     struct Instruction;
  47
  48     typedef ExecState CallFrame;
  49
  50     class Register {
  51         WTF_MAKE_FAST_ALLOCATED;
  52     public:
  53         Register();
  54
  55         Register(const JSValue&);
  56         Register& operator=(const JSValue&);
  57         JSValue jsValue() const;
  58         EncodedJSValue encodedJSValue() const;
  59
  60         Register& operator=(CallFrame*);
  61         Register& operator=(CodeBlock*);
  62         Register& operator=(ScopeChainNode*);
  63         Register& operator=(Instruction*);
  64         Register& operator=(InlineCallFrame*);
  65
  66         int32_t i() const;
  67         JSActivation* activation() const;
  68         CallFrame* callFrame() const;
  69         CodeBlock* codeBlock() const;
  70         JSObject* function() const;
  71         JSPropertyNameIterator* propertyNameIterator() const;
  72         ScopeChainNode* scopeChain() const;
  73         Instruction* vPC() const;
  74         InlineCallFrame* asInlineCallFrame() const;
  75         int32_t unboxedInt32() const;
  76         bool unboxedBoolean() const;
  77         JSCell* unboxedCell() const;
  78         int32_t payload() const;
  79         int32_t tag() const;
  80         int32_t& payload();
  81         int32_t& tag();
  82
  83         static Register withInt(int32_t i)
  84         {
  85             Register r = jsNumber(i);
  86             return r;
  87         }
  88
  89         static Register withCallee(JSObject* callee);
  90
  91     private:
  92         union {
  93             EncodedJSValue value;
  94             CallFrame* callFrame;
  95             CodeBlock* codeBlock;
  96             Instruction* vPC;
  97             InlineCallFrame* inlineCallFrame;
  98             EncodedValueDescriptor encodedValue;
  99         } u;
 100     };
 101
 102     ALWAYS_INLINE Register::Register()
 103     {
 104 #ifndef NDEBUG
 105         *this = JSValue();
 106 #endif
 107     }
 108
 109     ALWAYS_INLINE Register::Register(const JSValue& v)
 110     {
 111         u.value = JSValue::encode(v);
 112     }
 113
 114     ALWAYS_INLINE Register& Register::operator=(const JSValue& v)
 115     {
 116         u.value = JSValue::encode(v);
 117         return *this;
 118     }
 119
 120     ALWAYS_INLINE JSValue Register::jsValue() const
 121     {
 122         return JSValue::decode(u.value);
 123     }
 124
 125     ALWAYS_INLINE EncodedJSValue Register::encodedJSValue() const
 126     {
 127         return u.value;
 128     }
 129
 130     // Interpreter functions
 131
 132     ALWAYS_INLINE Register& Register::operator=(CallFrame* callFrame)
 133     {
 134         u.callFrame = callFrame;
 135         return *this;
 136     }
 137
 138     ALWAYS_INLINE Register& Register::operator=(CodeBlock* codeBlock)
 139     {
 140         u.codeBlock = codeBlock;
 141         return *this;
 142     }
 143
 144     ALWAYS_INLINE Register& Register::operator=(Instruction* vPC)
 145     {
 146         u.vPC = vPC;
 147         return *this;
 148     }
 149
 150     ALWAYS_INLINE Register& Register::operator=(InlineCallFrame* inlineCallFrame)
 151     {
 152         u.inlineCallFrame = inlineCallFrame;
 153         return *this;
 154     }
 155
 156     ALWAYS_INLINE int32_t Register::i() const
 157     {
 158         return jsValue().asInt32();
 159     }
 160
 161     ALWAYS_INLINE CallFrame* Register::callFrame() const
 162     {
 163         return u.callFrame;
 164     }
 165
 166     ALWAYS_INLINE CodeBlock* Register::codeBlock() const
 167     {
 168         return u.codeBlock;
 169     }
 170
 171     ALWAYS_INLINE Instruction* Register::vPC() const
 172     {
 173         return u.vPC;
 174     }
 175
 176     ALWAYS_INLINE InlineCallFrame* Register::asInlineCallFrame() const
 177     {
 178         return u.inlineCallFrame;
 179     }
 180
 181     ALWAYS_INLINE int32_t Register::unboxedInt32() const
 182     {
 183         return payload();
 184     }
 185
 186     ALWAYS_INLINE bool Register::unboxedBoolean() const
 187     {
 188         return !!payload();
 189     }
 190
 191     ALWAYS_INLINE JSCell* Register::unboxedCell() const
 192     {
 193 #if USE(JSVALUE64)
 194         return u.encodedValue.ptr;
 195 #else
 196         return bitwise_cast<JSCell*>(payload());
 197 #endif
 198     }
 199
 200     ALWAYS_INLINE int32_t Register::payload() const
 201     {
 202         return u.encodedValue.asBits.payload;
 203     }
 204
 205     ALWAYS_INLINE int32_t Register::tag() const
 206     {
 207         return u.encodedValue.asBits.tag;
 208     }
 209
 210     ALWAYS_INLINE int32_t& Register::payload()
 211     {
 212         return u.encodedValue.asBits.payload;
 213     }
 214
 215     ALWAYS_INLINE int32_t& Register::tag()
 216     {
 217         return u.encodedValue.asBits.tag;
 218     }
 219
 220 } // namespace JSC
 221
 222 namespace WTF {
 223
 224     template<> struct VectorTraits<JSC::Register> : VectorTraitsBase<true, JSC::Register> { };
 225
 226 } // namespace WTF
 227
 228 #endif // Register_h